I'm not sure what method you are using to back up data as you have not stated explicitly what you are doing. I have recently come across some people still using Mozbackup - I strongly advise you do not use that program as it has not been updated in over 12 years and even the author advises it has bugs and use at own risk.

The following is a simple and quick method of backing up everything.

I'm not sure whether you have imap or pop mail accounts but either way you have to ensure you have downloaded full copies of all emails in all folders. There is no point in backing up just headers, so check you have fully downloaded good copies of emails. Pop should have fully downloaded emails -

• Account Settings > Server Settings
• If you selected 'Fetch Headers only', then you have not downloaded full copies.
• Uncheck that option and then clickon the 'Get Messages' and see if you can get full downloaded copies from server.

Imap -

• Account Settings > Synchronisation & Storage.
• Select checkbox - 'keep messages in all folders for this computer'
• clickon 'Advanced..' button
• Select checkboxes for every folder and subfolder to get fully downloaded copies and clickon OK
• Under 'Disk Space'
• select 'Synchronise all messages locally regardless of age'

The force a synchronisation via 'Menu Bar' toolbar

• File > Offline > Download sync now
• Select 'Mail Messages'
• You can double check all required folders are selected using the 'Select...' button
• Click on OK's to start the sync.

I would also advise you compact all folders to remove all the old traces of moved or deleted emails. So you are backing up only wanted emails in the least size files.

• In Folder Pane
• select name of account folder and right click to see drop down menu and clickon 'Compact Folders'
• REpeat for each mail account name folder.

Now you ready to form a backup.

• Exit Thunderbird now - this is important.

Now perform the backup... Access where the profile is located - I'm assuming it is in the default Windows OS location.

• In windows search type: %Appdata% - see image below as guide.
• Select the %Appdata% file folder
• select the 'Roaming' folder
• Right click on the 'Thunderbird' folder and select 'Copy'
• Access external hardrive or where ever you put backup
• Right click and select 'Paste'

The 'Thunderbird' folder contains absolutely everything required should it be required as a backup. That includes 'profile.ini' files, profile name folders and files therein including emails, address books, calendar and all preferences including passwords etc. It also means it's easy to put a complete copy back on computer should you need to.

By the way Thunderbird works for any server that offers pop, imap and smtp access for emails. In some cases, the server requires that you need to switch on the options you want to use. Xfinity states you need to select a specific checkbox option to allow third part access. Some servers now require you to use 'app specific passwords' eg: yahoo - many email addresses use the yahoo server. Other servers like gmail and microsoft require you to use 'Authentication Method: Oauth2' for both receiving and sending and will prompt you to enter password in order to allow third party access to server.

REcently, Microsoft has changed a few more rules, Microsoft account password must be the same as outlook.com/hotmail.com/live.com/msn.com account/email address password. Microsoft has also now stated only one account will be classed as the main account - set up as 'primary' and any other email addess eg: outlook.com/hotmail.com/live.com/msn.com will be regarded as 'alias' account. This has an impact on sending using third party programs - no matter what the account email address used for receiving emails, it must use whatever is set up as 'primary' as the SMTP username. However, you do have the choice on what you choose to be as 'primary'.

I notice in a previous question you said - GMX does not work with Thunderbird It does, but as is the case for any email address on any server - obviously you do have to use very specific settings. Get any part wrong and it will fail.

I notice you also said : I read on THIS FORUM that Gmail did not work well with Thunderbird Not true, it works perfectly well. Thunderbird has no problem providing you use correct settings. In fact there has been huge progress recently when it comes to gmail. Now you easily hookup to the gmail Address Book and Calendar.

Info you may not be aware about:

When you attach any file(s) to an email you will increase the email size, which you probably already realise, but what you may not realise is the following: When email is prepared for sending the size increases by about a third due to base64 encoding sending two 8-bit characters as three 7-bit ASCII characters.

So, if you attach a file that is eg: 18 MB, then it real size will be close to 25MB and may fail because either your server will not allow sending of an email of that size or the receiving server cannot receive a file of that size. You have to consider not just whether your server will send it but whether the receiving server will accept it.

Advise you make sure any email you send has a total size not exceeding 16 MB, then you know it will not exceed 25MB.

Or less than 14MB, if the max is 20MB.

You could zip the file to make it smaller. Or if an image reduce the dpi or size to make smaller file.

Please note: In older version the word 'Options' was used - this was then replaced by the word 'Preferences' but in the most up to date recent version of Thunderbird is now replaced by 'Settings'.

Read this info on sending large files as attachments

• https://support.mozilla.org/en-US/kb/how-can-i-send-large-attachment

Info on FileLink for large attachments:

• https://support.mozilla.org/en-US/kb/filelink-large-attachments

FileLink is under 'Settings' > 'Composition' Scroll down to 'Attachments' which is at the bottom.

Three replies with a lot of information were a lot for this old woman! I'll be 77 in December. That said, I hope I am a little more computer literate than some old folks my age.

I really did read the things I said I read on this forum. You are probably correct that what I read wasn't accurate, but I did get them here.

Last summer, I was desperate to set up a new email address as our old email addresses were tied to our old ISP before we moved. Someone on this forum recommended GMX. I went as far as setting up the GMX addresses for my husband and myself. It was after that when I read either in the GMX info or in Thunderbird that GMX was not compatible. I very well remember being quite annoyed at the person who recommended GMX.

I fervently wish I had had you to tell me how to set up Thunderbird for GMX. MS Outlook has caused us problems as it sometimes doesn't want to communicate with BellSouth. I am also just not thrilled that Microsoft may be about to change this or that.

Right now, I am considering ditching Outlook for GMX. That would solve several problems though it would require notifying people we have ANOTHER new email address.

We have a local computer guy, but he isn't familiar with Thunderbird.

This is the answer to Toad Hall's first question about how I back up Thunderbird. I got this from someone named Stan on the Thunderbird help site. I am copying and pasting below the instructions I have used since 2013.

Thunderbird is INSTALLED to a folder in \Program Files - but there is no data there.

All your messages, folders, settings, preferences and more are in the Profile folder in your computer user account. This way when the computer is set up with more than one user account the other account(s) can have their own Thunderbird Profile (with their own messages and folders and settings). Kinda just like when when there is more than one user account, they can have separate and different desktops. They'll each also have their own 'My Documents' and settings for whatever browser is used will be for that particular user.

If you back up your Profile folder it will include all your messages and so on. If disaster hits, you can 'restore' that profile folder back to where it was or to another computer with Thunderbird and it'll be just like before.

It is fairly simple to manually back up your profile. This process just involves copying a single directory to a backup location. Most of the work is in finding where the profile folder is stored.

Go to Help > Troubleshooting Information, and where it says Profile Directory, click the 'Open Containing Folder' button. That is the Profile Folder, it's name is 8 random characters.default, ie xxxxxxxx.default. It's may be easier to see/copy if you go up one level.

Close Thunderbird and copy this folder to somewhere safe and you've backed up not only all your emails and folders but also all your settings and everything else you have set. You can restore it to any computer and TB will come up just as you left it.

See http://kb.mozillazine.org/Profile_backup Comment good answer! • Norris Wootton 6 months ago • • Norris Wootton 6 months ago • Stan, I did not see any data when I looked at the Thunderbird folder. You have confirmed that impression. I think I might actually be able to follow your directions, so I'll print your answer and try it tomorrow or Saturday. I am a morning person, so now is not good. Thanks so much!! • • Norris Wootton 6 months ago • I found it. This is wonderful. Thank you!!!!! I am a delighted 65-year-old non-geek person this evening. I am comfortable with copying folders to flash drives, but had no clue where to find the data. The mail folder in my profile is 3.69GB, so I know I've found the right thing.

Backing up the actual profile name folder does mean all your emails and address books etc get backed up. So you have been doing ok. But if you need to reuse that profile you would need to get instructions on how to proceed. Either you would need to only use it's contents and reuse an existing profile Or paste in the profile to the correct location and then create a new profile which would point to the one you had just copied over - why - because the data that knows the profile exists is located in the 'profiles.ini' file and that is not in the profile name folder - it's in the 'Thunderbird' folder - hence why I suggested you backed up the entire 'Thunderbird' folder which contains the profiles. I'm not talking about the program itself. No one needs to backup a program.

RE: MS Outlook has caused us problems as it sometimes doesn't want to communicate with BellSouth.

In previous questions you have stated - you have created an email address with outlook. So that means it's one of these...Outlook.com, hotmail.com, live.com, msn.com email addresses which are owned by Microsoft and they have their own servers. They have nothing to do with 'Bellsouth' who are owned by 'AT&T'. Perhaps you mean your Internet Service Provider is AT&T.

AS I know things are changing with Microsoft - let's make sure you can continue using outlook.com

I need to have some info: Some people decided not to use the standard User Account' on their computer. Instead they have a Microsoft Account. For example when they Start their computer, before they can get access to anything they get asked for a password to logon to computer but what account are you logging onto ? This is at the beginning before you even see desktop or Thunderbird.

• So when you start the computer, do you logon to a Microsoft Account or a User Account?

I need to know what settings you currently use. You can tell me the following or post an image which shows the information.

• Account Settings > Server Settings
• What are you using for 'Authenication Method' eg OAuth2 or Normal PAssword?
• SMTP settings ? What are you using for Authentication Method?

In Thunderbird

• Help > Troubleshooting Information
• Scroll down to 'Mail and News Accounts' section
• Copy all the data and then paste it into this forum question.

Once I understand your setup, I can help advise on what to do to make sure it continues to work ok. You may already be set up just fine, but it's worth seeing if all ok so you do not need to set up new email addresses. By the way...you can have more than one email address in Thunderbird. I have one with my ISP as well as gmail and a few others. If you have AT&T as your ISP then maybe you also have a free email address provided by them ?

I do want to get away from Outlook and use GMX instead. When Bellsouth and att messages started bouncing back to me, I called our ISP which is AT&T. The helpful person there was on the phone with me for 40 minutes. She finally concluded that the problem was not with AT&T.

Maybe I failed to adequately describe what happens when I send messages to bellsouth or to att. The emails seem to go out just fine. Then, a day or two later, I get back a message saying that the message was refused by the server. This happens ONLY with individuals who are using bellsouth or att. I have no problem with other addresses.

Lastly, we had a hard drive fry itself about two years ago. Our local computer guy through whom we bought the Dell computer was able to use my Thunderbird backup to restore everything. This tech says he doesn't know Thunderbird, but he still knew what to do.

Thank you for helpful hints. I am elderly and it was just too much info all at once.

We do not use a Microsoft login. We got Windows 11 by accident, but I am ignoring it as much as possible. I honestly don't think I can manage to set up Thunderbird for GMX on my own, but I do have local resources who may be able to help.

I have just this past week discovered that the man who recommended GMX actually did write me back with instructions! I never saw his message of a year ago until now. I am going to try what he said to do to make GMX work. I fervently wish I had seen it before we started using Outlook.